S&S A/C & Slipons April issue - Harley Forum

Spade5 · #1 03-21-2008, 10:38 AM

I have an 07 Wide Glide that is bone stock and I am very happy with it. I have no issues with the performance and am hesitant to change anything.

In the April issue there was an install article on page 186 about installing the S&S kit on a stock engine to see the power gains. I had not doubt the kit was good and would increase power but the thing that jumped out at me was nothing was done to adjust the fuel mixture.

I have always been under the impression that the HD system only really uses the 02 sensors at idle and and steady cruising. Basically it doesn't adjust much except for the EPA requirements. I believe the article said that the ECM would adapt to the new air cleaner and or pipes after 15 minutes of running time which to me is just dead opposite of what I and others have accepted about the HD system.

This makes me wonder why HD does the stage one download if the system can adjust itself. My guess is the S&S would flow at least as much additional air as the Stage 1 so what is the real deal?

I had been thinking about installing the S&S kit but did not know where to go with a fuel injection controller. I am happy with the bike in stock form and don't really need more power but would not mind a little better exhaust sound and I like the look of the S&S A/C cover.

Does anyone know the straight scoop on this?

hdnt1550 · #2 03-22-2008, 11:24 AM

I think the stock ecm without a down load will only re tune to the stock settings and the bike will always run lean just like a stock bike.

Cruiser85257 · #3 03-22-2008, 06:11 PM

Something is definitely not right about the article. I don't think there is not one single owner who has not had this experience. He goes to the dealer to get a stage one. That's an installation of an after market air kit and different exhaust. Either he has the dealer do it or inquires about having it done. The next thing the dealer does is recommend some sort of fuel mngt system. Usually a stage one download for the ECU, or some other after market system. Recommending the system because they tell you the air kit will further lean the Bike, which is running lean to begin with.

Now if the ECU truely adjusts itself as the article implies then why is it such a well guarded secret that the Moco doesn't tell it's Tech people working in the Dealerships? I have 5 dealerships in my area. Not one single person working for them has ever told me, "don't worry about a fuel mngt system, the Bike will adjust itslef".

No, what I hear instead is buy this unit for $500 and spend another 4 hours of labor having the bike tuned. Why is this necessary if the unit can tune itself?

Motorman7 · #4 03-25-2008, 01:03 PM

I have the same concerns also. I have looked at various sources and what i came back with is the simple fact that if the air intake is greater and everything else is unchanged then the bike will run leaner. When you add an exhaust change to the mix and the exhaust lets the engine breathe better, that is more air out as well as in, this adds to the leaner mixture in the engine.
My Electrcal Diagnostics Manual only states that the O2 sensors monitor the exhaust and adjust the fuel/air mix accordingly. The ECM is coded with certain parameters and apply to stock bikes only. When the part is not stock any longer then the ECM will not react to wider increases or decreases only those set at the factory for air intake and exhaust flow. If this was not the case and the ECM could adapt or "learn" to a wider selection of readings then why the stage 1 downloads and why the need for SERT and other ECM replacements.
It even states in catalogs that the engine will run leaner when you purchase a certain exhaust or air cleaner over the stock unit.
It sounds like a marketing ploy on selling aftermarket air cleaners to say the bike will self adjust. Harley engineers spend a lot of time getting the ECM to run under various circumstances, but this is with stock components. They have no way of knowing what aftermarket device will be added, and will probably tell you proceed at your own risk.
If much air flow is altered to the stock engine, then it would be prudent to look into an aftermarket ECM that is adjustable for air flow changes made.

Spade5 · #5 03-25-2008, 02:34 PM

I believe the S&S site recommends a fuel management system.

TrainMan · #6 04-03-2008, 01:32 PM

I was wondering about this article as well. I just purchased an 07 Night Train and have not had the opportunity to ride yet (the great spring weather !!) anyway it has Vance and Hines Big Radius pipes and I believe the stock A/C. I have pulled the plugs and they are definatley not looking like the bike is running lean. As far as I know the dealer just installed the pipes according to the work order that I got with the bike (previous owner installed the pipes) the milage that was indicated at that time was around 1100, the bike had been driven as the milage when I bought it was 3500. My question is, this bike seems to be running rich? Should I look at putting on a stage 1 A/C and then doing the download. This fuel injection thing is kinda confusing.